Gollum is the creature who owns the One Ring before Bilbo finds it in J.R.R. Tolkien’s The Hobbit. Bilbo encounters him beneath the Misty Mountains after becoming separated from Thorin’s company.
Gollum once had another name, Sméagol, and belonged to a Hobbit-like people. The Ring’s influence helped transform him physically and psychologically. He lives alone beside an underground lake, where he spends much of his time speaking to himself and calling the Ring “my precious.”
Bilbo wins the Ring during a riddle contest and initially does not know its full importance. The Hobbit presents the discovery differently in its earliest edition, but Tolkien later revised the relevant chapter so that it matched the darker history explained in The Lord of the Rings. Gollum therefore connects the two books both as a former Ring-bearer and as a continuing threat.